UBIFS: clean up LEB recovery function

This patch cleans up 'ubifs_recover_leb()' function and makes it more readable.
Move things which are done only once out of the loop and kill unneeded 'switch'
statement.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 28 insertions, 56 deletions

diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c
index 42b4512c46b0..7d922033d666 100644
--- a/fs/ubifs/recovery.c
+++ b/fs/ubifs/recovery.c
@@ -609,8 +609,8 @@ static int drop_incomplete_group(struct ubifs_scan_leb *sleb, int *offs)
 struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
                                          int offs, void *sbuf, int grouped)
 {
-        int err, len = c->leb_size - offs, need_clean = 0, quiet = 1;
-        int empty_chkd = 0, start = offs;
+        int ret = 0, err, len = c->leb_size - offs, need_clean = 0;
+        int start = offs;
         struct ubifs_scan_leb *sleb;
         void *buf = sbuf + offs;
 
@@ -624,8 +624,6 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
                 need_clean = 1;
 
         while (len >= 8) {
-                int ret;
-
                 dbg_scan("look at LEB %d:%d (%d bytes left)",
                          lnum, offs, len);
 
@@ -635,8 +633,7 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
                  * Scan quietly until there is an error from which we cannot
                  * recover
                  */
-                ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
-
+                ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 0);
                 if (ret == SCANNED_A_NODE) {
                         /* A valid node, and not a padding node */
                         struct ubifs_ch *ch = buf;
@@ -649,66 +646,37 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
                         offs += node_len;
                         buf += node_len;
                         len -= node_len;
-                        continue;
-                }
-
-                if (ret > 0) {
+                } else if (ret > 0) {
                         /* Padding bytes or a valid padding node */
                         offs += ret;
                         buf += ret;
                         len -= ret;
-                        continue;
-                }
-
-                if (ret == SCANNED_EMPTY_SPACE) {
-                        if (!is_empty(buf, len)) {
-                                if (!is_last_write(c, buf, offs))
-                                        break;
-                                clean_buf(c, &buf, lnum, &offs, &len);
-                                need_clean = 1;
-                        }
-                        empty_chkd = 1;
+                } else if (ret == SCANNED_EMPTY_SPACE ||
+                           ret == SCANNED_GARBAGE     ||
+                           ret == SCANNED_A_BAD_PAD_NODE ||
+                           ret == SCANNED_A_CORRUPT_NODE) {
+                        dbg_rcvry("found corruption - %d", ret);
                         break;
-                }
-
-                if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE)
-                        if (is_last_write(c, buf, offs)) {
-                                clean_buf(c, &buf, lnum, &offs, &len);
-                                need_clean = 1;
-                                empty_chkd = 1;
-                                break;
-                        }
-
-                if (ret == SCANNED_A_CORRUPT_NODE)
-                        if (no_more_nodes(c, buf, len, lnum, offs)) {
-                                clean_buf(c, &buf, lnum, &offs, &len);
-                                need_clean = 1;
-                                empty_chkd = 1;
-                                break;
-                        }
-
-                if (quiet) {
-                        /* Redo the last scan but noisily */
-                        quiet = 0;
-                        continue;
-                }
-
-                switch (ret) {
-                case SCANNED_GARBAGE:
-                        dbg_err("garbage");
-                        goto corrupted;
-                case SCANNED_A_CORRUPT_NODE:
-                case SCANNED_A_BAD_PAD_NODE:
-                        dbg_err("bad node");
-                        goto corrupted;
-                default:
-                        dbg_err("unknown");
+                } else {
+                        dbg_err("unexpected return value %d", ret);
                         err = -EINVAL;
                         goto error;
                 }
         }
 
-        if (!empty_chkd && !is_empty(buf, len)) {
+        if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE) {
+                if (is_last_write(c, buf, offs)) {
+                        clean_buf(c, &buf, lnum, &offs, &len);
+                        need_clean = 1;
+                } else
+                        goto corrupted_rescan;
+        } else if (ret == SCANNED_A_CORRUPT_NODE) {
+                if (no_more_nodes(c, buf, len, lnum, offs)) {
+                        clean_buf(c, &buf, lnum, &offs, &len);
+                        need_clean = 1;
+                } else
+                        goto corrupted_rescan;
+        } else if (!is_empty(buf, len)) {
                 if (is_last_write(c, buf, offs)) {
                         clean_buf(c, &buf, lnum, &offs, &len);
                         need_clean = 1;
@@ -751,6 +719,10 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
 
         return sleb;
 
+corrupted_rescan:
+        /* Re-scan the corrupted data with verbose messages */
+        dbg_err("corruptio %d", ret);
+        ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
 corrupted:
         ubifs_scanned_corruption(c, lnum, offs, buf);
         err = -EUCLEAN;